ENGLISH CHANNEL. 207 



The maximum of winds between S. and W. takes place in November and Deo. 

 The minimum „ ,, May and June. 



The maximum of winds between W. and N. takes place Ln July and August. 

 The minimxmi „ ,, October and December 



The maximum of winds between N. and E. takes place in May and June. 

 The minimum ,, ,, October and November. 



The maximum of winds between E. and S. takes place in December & January. 

 The minimum „ ,, June and July. 



Moderate winds from North and N.E. are those which bring fine weather. In 

 summer the N.E. wind blows more particularly in the afternoon; in the morning 

 the wind is S.E., a slight breeze, and towards noon it changes quickly to N.E. ; 

 then it freshens, and towards the evening it sinks ; at night it is calm, and the 

 coolness condenses the vapom-s. When this condensation does not take place, it 

 is a sign of a change of wind. 



Dead calms are of rare occmrrence, and do not last long, except during svunmer. 

 When they occur in winter, it is regarded as a precursor of bad weather. It ia 

 always, in reality, an indication of a change in the direction of the wind. 



(142.) The remarks made in the foregoing pages will be ample for the 

 purpose of giving the sailor an idea of the relative Duration, Force, and 

 Direction of the Wind in the Northern part of the North Atlantic Ocean. 

 Eeverting to the observation made on page 203, it may be re-stated, that not- 

 withstanding the variable nature of its changes, and the great difference 

 that is found to occur between one period and another, yet, when these are 

 combined in a long series of observations, there is great similarity ; and 

 this will be accounted for in a measure by the researches of our own and 

 the United States Meteorological Offices, which have shown that there is 

 a systematic progress of air from the Westward to the Eastward in our 

 latitudes (see pp. 181 — 198 and pp. 198 — 199). For the service of the 

 mariner, in foretelling what weather is approaching, he is referred to 

 Section 2, on the Motions and Pressure of the Atmosphere, and for further 

 information he can consult the " Barometer Manual for the use of Seamen", 

 or " Instructions in the use of Meteorological Instruments," issued by the 

 Meteorological Office, and to "Weather Charts and Storm Warnings," by 

 Robert H. Scott, M.A., F.E.S., &c. 



The diagrams adjoining page 171 have been drawn up from Maury's 

 Pilot Charts in the same manner as those given at page 135, to illustrate 

 the Trade Winds. They are selected from those parts of the ocean most 

 generally traversed by ships crossing it in the strength of these Westerly 

 winds, ^.heir localities are shown by the latitude and longitude assigned 

 to each diagram, which thus represents the wind in the region for 150 miles 

 around that position. But, as will be seen at a glance, there is a great 

 similarity in the general features of them all. 



The principle upon which these Wind-roses are constructed is explained 

 on page 133 (57) ; and the six examples there given are analyzed in page 

 134. The remark in the note (*) should be particularly attended to in 

 connection with the observations in these Anti-Trade winds, as it is clearly 

 futile to endeavour to lay down any refined rule for their practical applica- 



